Cell line is of great importance for basic research of cancer. In vitro experiments using cell lines and subsequent construction of animal models are the essential approaches to find out the potential functions of important genes in the postgenomic era, especially for the functional genomics era. At present, cell lines are still extensively used as an important tool for characterizing gene functions in vitro, due to their relatively steady genetic background. Tumor cell lines are of great importance not only for deeply exploring the mechanisms of tumorigenesis and progression at molecular or genetic level, but also for early diagnosis, medicine screening and cancer therapy. For example, treatment of metastatic clear cell RCC using sunitinib malate is now at phase III clinical trial, based on the in vitro function of this medicine on RCC cell lines such as 786-O.
Sarcomatoid RCC (sRCC) is a specific RCC entity, which accounts for only 1.0-8.0% of renal cell tumors and there are rare sRCC cases in clinic. sRCC presents highly aggressive malignancy, and progressions of sRCC patients go rapidly, usually with early metastasis. sRCC patients are not sensitivity to chemotherapy or radiotherapy and have extremely poor prognosis. The average survival time of T1 patients is 49.7 months, while it is 6.8 months for T2˜T4 patients. In 1968, Farrow and his colleagues firstly discovered and named sarcomatoid RCC (Farrow G M, Harrison E G, UTZ DG. Sarcomas and sarcomatoid and mixed malignant tumor s of the kidney in adults-Part III. Cancer 1968, 22: 556-563). For the components of this type of tumor, the epithelial component can be a renal cell carcinoma of various pathological types, 70% of which is clear cell or chromophobe granule type; while the sarcomatoid component can be hemangiopericytosarcomatoid, rhabdomyosarcomatoid, osteosarcomatoid, chondrosarcomatoid and undifferentiated sarcomatoid structure, et al. At present, early diagnosis with subsequent radical nephrectomy is preferred alternative of sRCC patients, since there is no breakthrough in diagnosis and treatment of sRCC. A few sRCC cases have been reported to be sensitive to cytokine therapy, which are only case reports and have not been verified by randomized control trials. Furthermore, prognosis and therapeutic effect are directly influenced by the proportion between the sarcomatoid and epithelia components in sRCC, in which the higher proportion the sarcomatoid component accounts for, the poorer the prognosis is, and the harder the systematic treatment will be. In order to elucidate the genetic properties of sRCC, particularly the effect of the interaction between the sarcomatoid and epithelia components on RCC malignancy, thereby guiding systematic treatment, it is required and necessary to establish sRCC cell lines.
At present, ATCC has not deposited any sRCC cell lines. Since the genetic background and living conditions varied among races all over the world, tumor morbidity and fatality rates are also different. Thus, it is the essential step and of great scientific value to establish the cell line of sRCC derived from Han Chinese, which contributed to exploring the mechanism of RCC metastasis.